Interaction between β blockers and epinephrine on hemodynamics of spontaneously hypertensive rats

本文观察了非选择性β肾上腺素能阻滞剂与肾上腺素的相互作用对自发性高血压大鼠（SHR）和Wistar京都大鼠（WKY）血流动力学的影响。（研究1）：给清醒的SHR和WKY腹腔注射非选择性β受体阻滞剂、吲哚洛尔和含1：80，000肾上腺素的2%利多卡因。吲哚洛尔预处理后，肾上腺素对WKY的血流动力学无明显影响。另一方面，SHR的血压显著升高。从这些观察，这表明，肾上腺素对外周血管床的作用在吲哚洛尔的存在下被夸大。在另一项研究中，苯乙哌啶被给予SHR和WKY腹腔内。SHR的血压升高较WKY明显。这一结果表明，SHR比WKY对刺激物更敏感。（研究2）：在丙泊酚、非选择性β受体阻滞剂、普拉洛尔静脉全麻下。SHR和WKY大鼠连续静脉注射肾上腺素。通过股动脉侵入性测量血压和心率。我们发现，在SHR和WKY中，肾上腺素与心得安组合引起血压显著升高。从这些观察结果可以看出，在普拉洛尔存在下，肾上腺素对外周血管床的影响被夸大。由于SHR的病理特点，异丙酚更易使其血管舒张。这可能是SHR和WKY之间血压无差异的原因。

We investigated the effects of the interaction between nonselective β adrenergic blocking agents and epinephrine on the hemodynamics in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY).(Study 1) : Nonselective β blocker, pindolol, and 2% lidocaine containing 1:80,000 epinephrine were administered to conscious SHR and WKY intraperitoneally Blood pressures and heart rate were measured by the photoplethysmografic tail cuff method. Epinephrine did not cause significant hemodynamic changes in WKY after the pindolol pretreatment. On the other hand, blood pressure increased significantly in SHR. From these observation, it was suggest that a effects of epinephrine on peripheral vascular bed was exaggerated in the presence of pindolol.In an additional study, fenylephrine was administered to SHR and WKY intraperitoneally. There was more marked increase in blood pressure in SHR than WKY. This result showed that SHR was more sensitive to a stimulator than WKY.(Study 2) : Under general anesthesia with propofol, nonselective β blocker, ploplanolol was injected intravenous. Then epinephrine was injected intravenous continuously to SHR and WKY. Blood pressure and heart rate were measured invasively through the femoral artery. We found that in both SHR and WKY, epinephrine in combination with proplanolol induced remarkable increase in blood pressure. From these observation, it was suggest that a effects of epinephrine on peripheral vascular bed was exaggerated in the presence of proplanolol. For the pathologic features, SHR is more prone to vasodilation by propofol. This might be the reason why there were no differences in bloodpressure between SHR and WKY.